Computational Engineering, Singapore-MIT Alliance, 4 Engineering Drive 3, Singapore 117576.
Lab Chip. 2011 Sep 21;11(18):3167-73. doi: 10.1039/c1lc20481e. Epub 2011 Aug 8.
We present a new method for separation of micro-sized constituents with positive acoustic contrast factors in a microfluidic channel using ultrasound. The ultrasound field is switched between the first and third resonant modes of the fluid channel, and the suspended constituents are separated onto the side and center pressure nodal lines according to their sizes or acoustic contrast factors. Initial hydrodynamic focusing of the constituents within a region of the channel near to the side nodal line is a crucial step in this separation method. This new method is shown to provide a novel "parallel-stream" separation of two species of particles with good robustness. Prior numerical simulations provide essential information on this operating region and also the voltage cycle to be applied to the ultrasonic actuators for optimal separation. Experiments were conducted using a prototype of the design with polystyrene microspheres of different sizes to demonstrate the efficiency and robustness of the separation process.
我们提出了一种新的方法，用于使用超声波在微流道中分离具有正声对比度因子的微尺度成分。超声波场在流道的第一和第三共振模式之间切换，根据尺寸或声对比度因子，悬浮成分被分离到侧面和中心压力节点线上。在靠近侧面节点线的流道区域内对成分进行初始的流体动力学聚焦是这种分离方法的关键步骤。这种新方法被证明能够提供两种粒子的新颖的“平行流”分离，具有很好的稳健性。先前的数值模拟提供了关于该操作区域的重要信息，以及为了实现最佳分离而要施加到超声换能器的电压周期。使用不同尺寸的聚苯乙烯微球的设计原型进行了实验，以证明分离过程的效率和稳健性。
